Research on multiplexed colour QR code with direct readability

With the rapid popularization of QR code technology, colour QR code is an important direction of its development, making it of great value to research a colour QR code that can be read directly while improving the data capacity. This letter proposes a novel composite colour QR code by combining colour coding and multiplexing technology. Based on the actual demands of high-capacity, this code presents the public identification information in the form of the plain code and conceals the secret information (e.g., authentication information such as traceability, blockchain) as the hidden code. The reading conditions of colour QR codes are discussed, a colour coding model is established and the corresponding algorithm to optimize its design is given. Through code scanning tests, it is verified that this kind of code has significant value in the field of anti-counterfeiting, commodity marketing etc.